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1.
BMC Psychiatry ; 24(1): 103, 2024 Feb 06.
Article de Anglais | MEDLINE | ID: mdl-38321403

RÉSUMÉ

BACKGROUND: Severe deterioration in mental health and disrupted care provision during the COVID-19 increased unmet needs for mental health. This review aimed to identify changes in mental health services for patients in response to the pandemic and understand the impact of the changes on patients and providers. METHODS: Following the Cochrane guidance for rapid reviews, Cochrane CENTRAL, MEDLINE, Embase and PsycInfo were searched for empirical studies that investigated models of care, services, initiatives or programmes developed/evolved for patients receiving mental health care during COVID-19, published in English and undertaken in high-income countries. Thematic analysis was conducted to describe the changes and an effect direction plot was used to show impact on outcomes. RESULTS: 33 of 6969 records identified were included reporting on patients' experiences (n = 24), care providers' experiences (n = 7) and mixed of both (n = 2). Changes reported included technology-based care delivery, accessibility, flexibility, remote diagnostics and evaluation, privacy, safety and operating hours of service provision. These changes had impacts on: (1) care access; (2) satisfaction with telehealth; (3) comparability of telehealth with face-to-face care; (4) treatment effectiveness; (5) continuity of care; (6) relationships between patients and care providers; (7) remote detection and diagnostics in patients; (8) privacy; (9) treatment length and (10) work-life balance. CONCLUSIONS: A shift to telecommunication technologies had a significant impact on patients and care providers' experiences of mental health care. Improvements to care access, flexibility, remote forms of care delivery and lengths of operating service hours emerged as crucial changes, which supported accessibility to mental health services, increased attendance and reduced dropouts from care. The relationships between patients and care providers were influenced by service changes and were vastly depending on technological literacy and context of patients and availability and care access ranging from regular contact to a loss of in-person contact. The review also identified an increase in care inequality and a feeling of being disconnected among marginalised groups including homeless people, veterans and ethic minority groups. Telehealth in mental care could be a viable alternative to face-to-face service delivery with effective treatment outcomes. Further research is needed to better understand the impact of the changes identified particularly on underserved populations.


Sujet(s)
COVID-19 , Services de santé mentale , Humains , Pandémies , Pays développés , Prestations des soins de santé
2.
BMC Health Serv Res ; 23(1): 1448, 2023 Dec 20.
Article de Anglais | MEDLINE | ID: mdl-38124113

RÉSUMÉ

BACKGROUND: Integrated care has become a central feature of health system reform worldwide. In England, Integrated Care Systems (ICS) are intended to improve integration across public health, the National Health Service (NHS), education and social care. By April 2021, England had been divided into 42 geographical areas, each tasked with developing local ICS provision. However, it was not clear how ICSs would address the specific needs of children and young people (CYP). This study elicited the views of senior professional stakeholders in the first year of the ICS national roll out, to learn how integrated care for CYP was being implemented within the ICSs and future plans for service provision. METHODS: A qualitative analysis of in-depth interviews with stakeholders, including healthcare professionals, NHS managers and local authority leaders (n = 25) selected from a diverse sample of ICSs (n = 7) across England, conducted during winter 2021/22. Reflexive thematic analysis involving a collaborative coding approach was used to analyse interview transcripts. RESULTS: Four themes were identified, indicating challenges and opportunities for ICSs in relation to the health of CYP: 1) Best start in life (a more holistic approach to health afforded by integrated care); 2) Local and national contexts (tensions between local and national settings and priorities); 3) Funding and planning (instituting innovative, long-term plans using limited existing CYP funding streams); 4) Organisational complexities (integrating the work of diverse organisations). CONCLUSIONS: The views of stakeholders, provided at the beginning of the journey towards developing local ICS CYP provision, revealed a common aspiration to change focus from provision of acute, largely adult-orientated services towards one with a broader, population health remit, including prevention and early intervention. This would be delivered by integration of a range of local services, including health, education, housing and social care, to set CYP on a life-long path towards improved health and wellbeing. Yet there was an awareness that change would take place over time within existing national policy and funding frameworks, and would require overcoming organisational barriers through further developing local collaborations and partnerships. As ICSs mature, the experiences of stakeholders should continue to be canvassed to identify practical lessons for successful CYP integrated care.


Sujet(s)
Prestation intégrée de soins de santé , Médecine d'État , Enfant , Adulte , Humains , Adolescent , Recherche qualitative , Personnel de santé , Angleterre/épidémiologie
3.
Int J Mol Sci ; 24(11)2023 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-37298596

RÉSUMÉ

A [3 + 2] cycloaddition reaction using dialkyne and diazide comonomers, both bearing explosophoric groups, to synthesize energetic polymers containing furazan and 1,2,3-triazole ring as well as nitramine group in the polymer chain have been described. The developed solvent- and catalyst-free approach is methodologically simple and effective, the comonomers used are easily available, and the resulting polymer does not need any purification. All this makes it a promising tool for the synthesis of energetic polymers. The protocol was utilized to generate multigram quantities of the target polymer, which has been comprehensively investigated. The resulting polymer was fully characterized by spectral and physico-chemical methods. Compatibility with energetic plasticizers, thermochemical characteristics, and combustion features indicate the prospects of this polymer as a binder base for energetic materials. The polymer of this study surpasses the benchmark energetic polymer, nitrocellulose (NC), in a number of properties.


Sujet(s)
Polymères , Triazoles , Polymères/composition chimique , Triazoles/composition chimique , Plastifiants/composition chimique , Dérivés de l'aniline
4.
Int J Integr Care ; 23(2): 18, 2023.
Article de Anglais | MEDLINE | ID: mdl-37250761

RÉSUMÉ

Introduction: Robust measures of integration are essential for assessment of the development, design and implementation of integration within healthcare systems. This review aimed to identify measurement instruments for integration within children and young people's (CYP) healthcare systems (PROSPERO registration number CRD42021235383). Methods: We searched electronic databases (PubMED and Ovid Embase) using three main concepts: '(integrated care) AND (child population) AND (measurement)', along with additional searches. Results: Fifteen studies describing 16 measurement instruments were eligible for inclusion. The majority of studies were conducted in the USA. There was a diversity of health conditions included in the studies. The most frequent type of assessment used was a questionnaire (11 identified), but interviews, patient data and healthcare records, and focus groups were also used. Integration outcomes assessed were quality of care coordination, quality of collaboration, continuity of care, completeness of care, structure of care, quality of communication, and local implementation of integrated care. Conclusion: A variety of instruments for the measurement of integration within CYP healthcare systems were identified. Further work on the standardisation of integrated care measures would be valuable; however, it is important that instruments and measures meet the needs of specific settings, populations and conditions being studied.

5.
Molecules ; 29(1)2023 Dec 22.
Article de Anglais | MEDLINE | ID: mdl-38202662

RÉSUMÉ

Optical methods (spectroscopy, spectrofluorometry, dynamic light scattering, and refractometry) were used to study the change in the state of hen egg-white lysozyme (HEWL), protein molecules, and gold nanoparticles (AuNPs) in aqueous colloids with changes in pH, and the interaction of protein molecules with nanoparticles was also studied. It was shown that changing pH may be the easiest way to control the protein corona on gold nanoparticles. In a colloid of nanoparticles, both in the presence and absence of protein, aggregation-deaggregation, and in a protein colloid, monomerization-dimerization-aggregation are the main processes when pH is changed. A specific point at pH 7.5, where a transition of the colloidal system from one state to another is observed, has been found using all the optical methods mentioned. It has been shown that gold nanoparticles can stabilize HEWL protein molecules at alkaline pH while maintaining enzymatic activity, which can be used in practice. The data obtained in this manuscript allow for the state of HEWL colloids and gold nanoparticles to be monitored using one or two simple and accessible optical methods.


Sujet(s)
Nanoparticules métalliques , Lysozyme , Or , Colloïdes , Concentration en ions d'hydrogène
6.
Molecules ; 27(22)2022 Nov 10.
Article de Anglais | MEDLINE | ID: mdl-36431845

RÉSUMÉ

A simple, mild and general method has been developed for the preparation of alkyl nitramines bearing a halogenoalkoxylic moiety. From these reactive halogen intermediates, a few azidoalkoxyl alkyl nitramines have been produced as energetic plasticizers. This simple protocol allows azidonitramino ether plasticizers to be obtained from available precursors in high yields, as it is safe and viable for large-scale operations. The resulting products have been fully characterized by spectral methods, and their impact sensitivity, thermal transformations and burning properties were determined, thus allowing complete comparison to the analogues including other combinations of structural units. Such characterization of these new plasticizers illustrates the extent to which the nature and position of the functional units can be used to tune the above properties of these nitramines. All azidonitramino ethers are liquid with excellent energetic performance and are promising candidates for new environmentally friendly energetic materials.

7.
Biomed Pharmacother ; 109: 2548-2560, 2019 Jan.
Article de Anglais | MEDLINE | ID: mdl-30551515

RÉSUMÉ

Melanoma is one of the most aggressive and treatment-resistant tumors that responsible for majority of skin-cancer related deaths. Here we propose a combination of MEK inhibitor binimetinib with metformin as a promising therapy against human melanoma cells in vitro, including BRAF -mutated A375, Mel Z, and Mel IL cells, and NRAS-mutated Mel MTP and Mel Me cells. Additionally, we obtained two close to clinical practice models of melanoma progression. The first one was vemurafenib-resistant Mel IL/R melanoma cells with acquired resistance to BRAF inhibition-targeted therapy, and the second one was tumor spheroids, which are 3D in vitro model of small-size solid tumors in vivo. The cytotoxicity of binimetinib and metformin was synergistic in both 2D and 3D melanoma culture and mediated through apoptotic pathway. The combination reduced the number of melanoma-formed colonies, inhibited cell invasion and migration, and led to G0/G1 cell cycle arrest through cyclin D/CDK4/CDK6 pathway. The mechanism of metformin and binimetinib synergy in melanoma cells was associated with increased activation of p-AMPKα and decreased p-ERK, but not with alterations in p-mTOR. In summary, the combination of metformin and binimetinib resulted in stronger anti-proliferative effects on melanoma cells compared to binimetinib alone, and therefore could be promising for clinical applications.


Sujet(s)
Benzimidazoles/administration et posologie , MAP Kinase Kinase 1/antagonistes et inhibiteurs , MAP Kinase Kinase 2/antagonistes et inhibiteurs , Mélanome/enzymologie , Metformine/administration et posologie , Protocoles de polychimiothérapie antinéoplasique/administration et posologie , Lignée cellulaire tumorale , Relation dose-effet des médicaments , Synergie des médicaments , Humains , Hypoglycémiants/administration et posologie , Mélanome/traitement médicamenteux , Inhibiteurs de protéines kinases/administration et posologie
8.
Oncol Rep ; 40(1): 385-394, 2018 Jul.
Article de Anglais | MEDLINE | ID: mdl-29749510

RÉSUMÉ

The incidence of malignant melanoma is increasing. The discovery of agents specifically targeting the mutated cascades has provided a good response for patients with oncogenic B-Raf proto-оncogene, serine/threonine kinase (BRAF). However, numerous studies continue to focus on novel methods of treatment to overcome acquired resistance to novel drugs. Recently, it has been revealed that inhibition of endoplasmic reticulum (ER) stress chaperon 78 kDa glucose-regulated protein 78 (GRP78) leads to down-regulation of autophagy and increased sensitivity to temozolomide (TMZ) treatment. Melanoma cells have a different sensitivity to TMZ treatment, which corresponds to the basal autophagy level. In the present study, we demonstrated that downregulation of GRP78 mitigated chemoresistance to TMZ in three melanoma cell lines. We found that downregulation of GRP78 led to inhibition of autophagy, cell cycle arrest in the G0/G1 phase, and activation of caspase-7-induced apoptosis, and this was affected by the initial autophagy level. Moreover, inhibition of GRP78 mitigated the combined TMZ and chloroquine effect. Our data revealed that autophagy inhibition through downregulation of ER stress response could overcome resistance to TMZ treatment in melanoma cells with a high basal level of autophagy treatment, which makes this combination a potential potent antitumor treatment for metastatic melanoma.


Sujet(s)
Dacarbazine/analogues et dérivés , Stress du réticulum endoplasmique/effets des médicaments et des substances chimiques , Protéines du choc thermique/génétique , Mélanome/traitement médicamenteux , Animaux , Apoptose/effets des médicaments et des substances chimiques , Autophagie/effets des médicaments et des substances chimiques , Caspase-7/génétique , Lignée cellulaire tumorale , Dacarbazine/administration et posologie , Chaperonne BiP du réticulum endoplasmique , Régulation de l'expression des gènes tumoraux/effets des médicaments et des substances chimiques , Humains , Mélanome/génétique , Mélanome/anatomopathologie , Souris , Protéines proto-oncogènes B-raf/génétique , Témozolomide , Tests d'activité antitumorale sur modèle de xénogreffe
9.
Oncotarget ; 8(32): 52304-52320, 2017 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-28881731

RÉSUMÉ

Target inhibitors are used for melanoma treatment, and their effectiveness depends on the tumor genotype. We developed a diagnostic biochip for the detection of 39 clinically relevant somatic mutations in the BRAF, NRAS, KIT, GNAQ, GNA11, MAP2K1 and MAP2K2 genes. We used multiplex locked nucleic acid (LNA) PCR clamp for the preferable amplification of mutated over wild type DNA. The amplified fragments were labeled via the incorporation of fluorescently labeled dUTP during PCR and were hybridized with specific oligonucleotides immobilized on a biochip. This approach could detect 0.5% of mutated DNA in the sample analyzed. The method was validated on 253 clinical samples and six melanoma cell lines. Among 253 melanomas, 129 (51.0%) BRAF, 45 (17.8%) NRAS, 6 (2.4%) KIT, 4 (1.6%) GNAQ, 2 (0.8%) GNA11, 2 (0.8%) MAP2K1 and no MAP2K2 gene mutations were detected by the biochip assay. The results were compared with Sanger sequencing, next generation sequencing and ARMS/Scorpion real-time PCR. The specimens with discordant results were subjected to LNA PCR clamp followed by sequencing. The results of this analysis were predominantly identical to the results obtained by the biochip assay. Infrequently, we identified rare somatic mutations. In the present study we demonstrate that the biochip-based assay can effectively detect somatic mutations in approximately 70% of melanoma patients, who may require specific targeted therapy.

10.
Invest New Drugs ; 35(2): 127-133, 2017 04.
Article de Anglais | MEDLINE | ID: mdl-27812884

RÉSUMÉ

SUMMAY: Purpose Early data suggest that combining FGFR2 inhibitors with platinum-containing cytotoxic agents for the treatment of epithelial ovarian cancer may yield increased antitumor activity. We investigated antitumor activity of alofanib (RPT835), a novel allosteric FGFR2 inhibitor, in ovarian cancer in vitro and in vivo. Methods Equal amounts of ovarian cancer cell (SKOV3) lysates were analyzed for FGFR1-3 protein expression using Wes. To assess the efficacy of alofanib on FGF-mediated cell proliferation, SKOV3 cells were incubated and were treated with serially diluted alofanib. Basic FGF was added at a concentration of 25 ng/ml. Control wells were left untreated. Cell growth inhibition was determined using Promega's Cell Titer-Glo® assay. Immunocompromised mice were used for xenotransplantation of SKOV3 cancer cells. Seventy animals with measurable tumors were selected on day 10 and randomized into control groups (no treatment or chemotherapy alone (paclitaxel + carboplatin) and treatment groups (alofanib orally or intravenously (different dose levels) in combination with chemotherapy). Measurements of tumor volume (mm3) were performed by digital calipers every 3 days during 31 days after tumor inoculation. Number of tumor vessels and Ki-67 index were calculated. Results SKOV3 cells express FGFR1 and FGFR2 but not FGFR3. Basic FGF increased proliferation of the ovarian cancer cells in untreated control group (P = 0.001). Alofanib inhibited growth of FGFR2-expressing SKOV3 cells with GI50 value of 0.37 µmol/L. Treatment with alofanib in combination with paclitaxel/carboplatin resulted in tumor growth delay phenotype in all treatment groups compared to control non-treatment groups. Compound exhibited a dose-dependent effect on tumor growth. Daily intravenous regimen of alofanib (total maximum dose per week was 350 mg/kg) demonstrated significant effect (inhibiting growth by 80 % and by 53 % in comparison with vehicle and chemotherapy group alone, respectively (P < 0.001). Alofanib decreased number of vessels in tumor (-49 %; P < 0.0001) and number of Ki-67-positive SKOV3 cells (-42 %, P < 0.05). There were tumor necrosis and cell degeneration in alofanib group. Conclusions We suggest that FGFR2 inhibition has potent effects on ovarian cancer growth in preclinical studies.


Sujet(s)
Antinéoplasiques/usage thérapeutique , Benzoates/usage thérapeutique , Tumeurs de l'ovaire/traitement médicamenteux , Inhibiteurs de protéines kinases/usage thérapeutique , Récepteur FGFR2/antagonistes et inhibiteurs , Sulfonamides/usage thérapeutique , Animaux , Antinéoplasiques/pharmacologie , Protocoles de polychimiothérapie antinéoplasique/usage thérapeutique , Benzoates/pharmacologie , Carboplatine/usage thérapeutique , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Femelle , Humains , Souris nude , Néovascularisation pathologique/traitement médicamenteux , Tumeurs de l'ovaire/métabolisme , Tumeurs de l'ovaire/anatomopathologie , Paclitaxel/usage thérapeutique , Inhibiteurs de protéines kinases/pharmacologie , Récepteur FGFR1/métabolisme , Récepteur FGFR2/métabolisme , Récepteur de type 3 des facteurs de croissance fibroblastique/métabolisme , Sulfonamides/pharmacologie , Charge tumorale/effets des médicaments et des substances chimiques
12.
Anticancer Drugs ; 28(3): 307-315, 2017 03.
Article de Anglais | MEDLINE | ID: mdl-27941537

RÉSUMÉ

Patients with metastatic melanoma are difficult to treat and have a very poor prognosis because of high resistance to therapy. Recent evidence indicates that tumors could overcome death through autophagy, a survival mechanism, which cancer cells use under lack of energy and nutrient deprivation. Melanoma cells have different sensitivity to temozolomide (TMZ) treatment. In this study, we showed that the combination of autophagy inhibitors chloroquine or LY294002 and TMZ induced enhanced cytotoxicity of alkylating agents on human melanoma cell lines. All assays were performed on patient-derived melanoma cell lines. The effectiveness of the combined treatment of TMZ and autophagy inhibitors was determined using an MTT assay. Next, we analyzed the expression mRNA level of Beclin 1, LC3B, and p62/STSQM1 and the relative expression of LC3B protein under combined treatment. Autophagic flux was determined by analysis of colocalization of Lysotracker Red and LC3B puncta. Apoptosis was measured by Annexin V/PI staining. Cell cycle analyses were carried out by flow cytometry. We showed that autophagy inhibition could enhance melanoma cell death combined with TMZ therapy. Chloroquine synergistically enhanced the TMZ-induced growth arrest and increased the G0/G1 population in Mel Z and Mel IL cell lines, but not Mel MTP. The expression analysis showed that autophagy involvement in TMZ enhanced cytotoxicity. Furthermore, LY294002, an early-stage autophagy, and PI3K inhibitor were found to exert similar effects. Both chloroquine and LY294002 improved the cytotoxic effect of TMZ treatment, making this combination applicable as a potent antitumor treatment for metastatic melanoma.


Sujet(s)
Protocoles de polychimiothérapie antinéoplasique/pharmacologie , Chloroquine/pharmacologie , 4H-1-Benzopyran-4-ones/pharmacologie , Dacarbazine/analogues et dérivés , Mélanome/traitement médicamenteux , Morpholines/pharmacologie , Tumeurs cutanées/traitement médicamenteux , Apoptose/effets des médicaments et des substances chimiques , Autophagie/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Chloroquine/administration et posologie , 4H-1-Benzopyran-4-ones/administration et posologie , Dacarbazine/administration et posologie , Dacarbazine/pharmacologie , Synergie des médicaments , Humains , Mélanome/anatomopathologie , Morpholines/administration et posologie , Tumeurs cutanées/anatomopathologie , Témozolomide
13.
Eur J Cancer ; 61: 20-8, 2016 07.
Article de Anglais | MEDLINE | ID: mdl-27136102

RÉSUMÉ

Alofanib (RPT835) is a novel selective allosteric inhibitor of fibroblast growth factor receptor 2 (FGFR2). We showed previously that alofanib could bind to the extracellular domain of FGFR2 and has an inhibitory effect on FGF2-induced phoshphorylation of FRS2α. In the present study, we further showed that alofanib inhibited phosphorylation of FRS2α with the half maximal inhibitory concentration (IC50) values of 7 and 9 nmol/l in cancer cells expressing different FGFR2 isoforms. In a panel of four cell lines representing several tumour types (triple-negative breast cancer, melanoma, and ovarian cancer), alofanib inhibited FGF-mediated proliferation with 50% growth inhibition (GI50) values of 16-370 nmol/l. Alofanib dose dependently inhibited the proliferation and migration of human and mouse endothelial cells (GI50 11-58 nmol/l) compared with brivanib and bevacizumab. Treatment with alofanib ablated experimental FGF-induced angiogenesis in vivo. In a FGFR-driven human tumour xenograft model, oral administration of alofanib was well tolerated and resulted in potent antitumour activity. Importantly, alofanib was effective in FGFR2-expressing models. These results show that alofanib is a potent FGFR2 inhibitor and provide strong rationale for its evaluation in patients with FGFR2-driven cancers.


Sujet(s)
Inhibiteurs de l'angiogenèse/pharmacologie , Antinéoplasiques/pharmacologie , Benzoates/pharmacologie , Thérapie moléculaire ciblée/méthodes , Récepteur FGFR2/antagonistes et inhibiteurs , Sulfonamides/pharmacologie , Animaux , Lignée cellulaire tumorale , Mouvement cellulaire/effets des médicaments et des substances chimiques , Prolifération cellulaire/effets des médicaments et des substances chimiques , Modèles animaux de maladie humaine , Cellules endothéliales/effets des médicaments et des substances chimiques , Cellules endothéliales de la veine ombilicale humaine/effets des médicaments et des substances chimiques , Humains , Souris , Tests d'activité antitumorale sur modèle de xénogreffe
14.
Invest New Drugs ; 31(6): 1436-43, 2013 Dec.
Article de Anglais | MEDLINE | ID: mdl-24026432

RÉSUMÉ

Fibroblast growth factor (FGF) receptor 1 (FGFR1) is a potential therapeutic target for treatment of metastatic renal cell carcinoma (RCC). We investigated the preclinical activity of OM-RCA-01, a novel therapeutic humanized anti-FGFR1 antibody in RCC. OM-RCA-01 has been shown to inhibit in vitro kinase activity of FGFR1 and has high affinity (Kd of 1.59 nM). In human renal carcinoma Caki-1 FGFR1-expressing cells, OM-RCA-01 potently inhibited FGF-mediated signaling and proliferation. In vivo, the tumors in untreated mice or mice treated with non-specific IgG continued their aggressive growth to reach the size of 2,000 cm3, at which point the mice were killed. In contrast, treatment with OM-RCA-01 not only significant arrested further growth of the tumors (P < 0.01) but also demonstrated differences in tumor volume compared with vehicle already on Day 13. A similar anti-tumor activity of OM-RCA-01 was observed when the antibody was given in low (1 mg/kg) or high (10 mg/kg) doses (P = 0.917). In Matrigel assay, OM-RCA-01 significantly inhibited FGF-induced endothelial cell migration, capillary-like tubular structure and mature vessels formation. Administration of 10 mg/kg antibody for up to 35 days resulted in minimal body weight loss and no observations of gross toxicity were made. Collectively, the data obtained with OM-RCA-01 are consistent with potent inhibition of FGFR1-signaling, angiogenesis, and tumor growth. OM-RCA-01 is being developed clinically as an intravenous therapy for the treatment of clear cell RCC.


Sujet(s)
Anticorps monoclonaux humanisés/usage thérapeutique , Antinéoplasiques/usage thérapeutique , Néphrocarcinome/traitement médicamenteux , Tumeurs du rein/traitement médicamenteux , Récepteur FGFR1/immunologie , Animaux , Néphrocarcinome/immunologie , Lignée cellulaire , Lignée cellulaire tumorale , Femelle , Humains , Immunoglobuline G/immunologie , Tumeurs du rein/immunologie , Souris , Souris nude , Tests d'activité antitumorale sur modèle de xénogreffe
15.
Biochimie ; 94(6): 1368-75, 2012 Jun.
Article de Anglais | MEDLINE | ID: mdl-22440655

RÉSUMÉ

Tumstatin, a cleavage fragment of collagen IV, is a potent endogenous inhibitor of angiogenesis. Tumstatin-derived peptide T8 possesses all angiostatic properties of full-length tumstatin and indirectly suppresses tumor growth. The potential of T8 to block pathological angiogenesis in the eye has not been explored yet. Here we assess antiangiogenic effects of a recombinant T8 peptide in rabbit corneal neovascularization models. The fusion protein consisting of T8 and thioredoxin was synthesized in a highly efficient Escherichia coli expression system, isolated using ion-exchange chromatography and cleaved with TEV (tobacco etch virus) protease. The target peptide was purified on an anion-exchange resin and by reversed phase high-performance liquid chromatography. The recombinant peptide suppressed the proliferation of basic fibroblast growth factor-induced SVEC-4-10 endothelial cells (simian virus 40-immortalized murine endothelial cells) and inhibited tube formation in these cells in a dose-dependent manner. In rabbit corneal neovascularization models T8 demonstrated the ability to prevent pathological angiogenesis (when injected simultaneously with the induction of neovascularization) and, moreover, to promote the regression of newly-formed blood vessels (when injected on day 8 after angiogenesis stimulation). Our results suggest that T8 may have a therapeutic potential in the treatment of ocular neovascular diseases.


Sujet(s)
Autoantigènes/usage thérapeutique , Collagène de type IV/usage thérapeutique , Néovascularisation cornéenne/traitement médicamenteux , Néovascularisation pathologique/métabolisme , Fragments peptidiques/usage thérapeutique , Protéines de fusion recombinantes/usage thérapeutique , Animaux , Autoantigènes/composition chimique , Collagène de type IV/composition chimique , Cellules endothéliales/effets des médicaments et des substances chimiques , Souris , Lapins
16.
Bioorg Med Chem ; 18(18): 6905-13, 2010 Sep 15.
Article de Anglais | MEDLINE | ID: mdl-20708939

RÉSUMÉ

Novel derivatives of tris(indol-3-yl)methane and tris(indol-3-yl)methylium salts with the alkyl substituents at the N-atoms of the indole rings were synthesized. An easy substitution of indole rings in trisindolylmethanes for other indoles under the action of acids is demonstrated, and the mechanism of substitution is discussed. To obtain trisindolylmethylium salts, the environmentally safe method of oxidation of trisindolylmethanes with air oxygen in acidic conditions was developed. Tris(1-alkylindol-3-yl)methanes and tris(1-alkylindol-3-yl)methylium salts represent three-bladed molecular propellers whose physico-chemical and biological properties strongly depend on the N-alkyl substituent. The cytotoxicity of novel compounds increased with the number of C atoms in the alkyl chains, with optimal number n=3-5 whereas the derivatives with longer side chains were less cytotoxic. The most potent novel compounds killed human tumor cells at nanomolar-to-submicromolar concentrations, being one order of magnitude more potent than the prototype antibiotic turbomycin A [tris(indol-3-yl)methylium salt]. Apoptosis in HCT116 colon carcinoma cell line induced by tris(1-pentyl-1H-indol-3-yl)methylium methanesulfonate was detectable at concentrations tolerable by normal blood lymphocytes. Thus, N-alkyl substituted tris(1-alkylindol-3-yl)methylium salts emerge as perspective anticancer drug candidates.


Sujet(s)
Antinéoplasiques/synthèse chimique , Indoles/composition chimique , Méthane/analogues et dérivés , Antinéoplasiques/composition chimique , Antinéoplasiques/toxicité , Lignée cellulaire tumorale , Humains , Indoles/synthèse chimique , Indoles/toxicité , Méthane/composition chimique , Sels/composition chimique
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